The present disclosure relates to a recording element substrate and a method of manufacturing the recording element substrate.
A liquid ejection apparatus such as an inkjet printer ejects liquid to record an image, characters, and the like on a recording medium such as paper. The liquid ejection apparatus includes a liquid ejection head as a part for ejecting liquid. The liquid ejection head includes a recording element substrate. The recording element substrate is provided with an ejection port forming member including ejection ports ejecting liquid, and a substrate on which the ejection port forming member is placed. Further, the substrate is provided with energy generation elements that generate energy to eject liquid from the ejection ports, and a liquid supply port that supplies liquid to the ejection ports.
Japanese Patent Application Laid-Open No. 2002-326363 discusses a method of manufacturing such a liquid ejection head including the recording element substrate. In the method discussed in Japanese Patent Application Laid-Open No. 2002-326363, after the liquid supply port is formed in the substrate, the liquid supply port is filled with a filler, and then the ejection port forming member is formed.
In the method discussed in Japanese Patent Application Laid-Open No. 2002-326363, however, bubbles may be trapped in with the filler in some cases.
If such bubbles are expanded by, for example, heat, the bubbles influences the flatness of the tape 25, and eventually influences the flatness of the ejection port forming member. As a result, there is concern that the bubble influences the accuracy of the ejection ports and also influences printing quality when liquid droplets are ejected from the ejection ports.
The present disclosure is directed to a recording element substrate that can prevent bubbles being trapped inside a liquid supply port formed perpendicularly with respect to a substrate when the liquid supply port is filled with a filler, and to a method of manufacturing the recording element substrate.
According to an aspect of the present disclosure, a recording element substrate includes an ejection port forming member in which an ejection port configured to eject liquid is formed, and a substrate including a liquid supply port configured to supply the liquid to the ejection port, a first surface on which the ejection port forming member is placed, and a second surface that is a rear surface of the first surface, wherein the liquid supply port includes a first portion perpendicularly connected to the first surface, and a second portion connected to the first portion, wherein an inner wall of the second portion includes an inclined surface that is inclined toward an inner wall of the first portion such that a width of the second portion is gradually increased toward the second surface, and wherein a hydrophilic film is formed at least on the inner wall of the first portion.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Some exemplary embodiments of the present disclosure are described with reference to drawings. In the following description, components having the same functions are denoted by the same reference numerals in the drawings, and descriptions thereof are omitted here in some cases.
The recording element unit 41 mainly includes recording element substrates 44 and 45 including ejection ports 11 (
The housing unit 42 mainly includes a housing 43 to which a liquid container (not illustrated) storing liquid to be supplied to the ejection ports 11 (
The recording element substrate 44 is described with reference to
The energy generation elements 2 are electrically connected to terminals 49 provided on the substrate 10 via electric wires (not illustrated) made of aluminum or the like. A plating layer made of, for example, gold (Au layer) is provided on a surface of each of the terminals 49.
The recording element substrate 44 is electrically connected to the electric wiring substrate 48 via the terminals 49. The energy generation elements 2 generate ejection energy to eject the liquid such as ink, by receiving an electric signal from the electric wiring substrate 48.
The ejection port forming member 9 forms the ejection ports 11 to eject the liquid, and pressure chambers 12 communicating with the ejection ports 11. The substrate 10 includes a liquid supply port 13, and the liquid is supplied from the liquid supply port 13 to the pressure chambers 12. The liquid supply port 13 is a through hole penetrating through the substrate 10. Further, the substrate 10 has a rectangular shape extending along a direction where the energy generation elements 2 are arranged. A transverse direction of the substrate 10 is referred to as an X direction, and a longitudinal direction orthogonal to the X direction is referred to as a Y direction.
Further, various inorganic films other than the oxide film 4 may be provided as necessary. The oxide film 4 is to protect the substrate 10 from liquid, and the adhesion improving layer 20 is to enhance adhesiveness between the substrate 10 and the ejection port forming member 9.
The liquid supply port 13 includes first liquid flow paths 51 perpendicularly connected to the first surface 21, and a second liquid flow path 52 connected to the second surface 22. In this specification, the expression of being perpendicularly connected to a component not only means a case of being connected to the component at an angle of 90 degrees, but also may consider variation caused by manufacturing errors of the first liquid flow paths 51. In other words, it is sufficient if the first liquid flow paths 51 are each substantially perpendicularly connected to the first surface 21, i.e., the first liquid flow paths 51 are each connected to the first surface 21 at an angle of 90±5 degrees.
The first liquid flow paths 51 and the second liquid flow path 52 are connected to each other. The liquid is supplied from the second liquid flow path 52 to the first liquid flow paths 51, and the liquid is further supplied from the first liquid flow paths 51 to the ejection ports 11. The first liquid flow paths 51 perpendicularly connected to the first surface 21 are also referred to as first portions 61. Further, in the second liquid flow path 52, a region including a portion where an inner wall is inclined is referred to as a second portion 62, and a portion where one end is connected to an inclined surface of the inner wall of the second portion 62 and the other end is perpendicularly connected to the second surface 22 is referred to as a third portion. In other words, in
The inner wall of the second portion 62 includes an inclined surface 23 inclined toward the inner walls of the first portions 61 such that a width of the second portion 62 in the transverse direction (X direction) is gradually increased toward the second surface 22. In other words, the second liquid flow path 52 is connected to the first portions 61 via the inclined surface 23.
In the first exemplary embodiment, hydrophilic films 24 are provided on the inner walls of the first portions 61. The reason for forming the hydrophilic films 24 and a method of forming the hydrophilic films 24 are described in detail below.
Thereafter, a plurality of blind holes (hereinafter, guide holes 31) each having a predetermined depth from the second surface 22 side is formed in the region to be opened, by using a laser. As described above, the inner wall of the second portion 62 needs to have the inclined surface 23 inclined toward the inner walls of the first portions 61 such that the width of the second portion 62 in the transverse direction is gradually increased toward the second surface 22. Therefore, as illustrated in
As the liquid-flow-path wall-surface protection film 18, a positive photosensitive resin is usable. As an application method, various kinds of application methods such as spin coating and curtain coating are usable. The liquid-flow-path wall-surface protection film 18 desirably has a film thickness of, for example, about 2 μm to 10 μm, but may have another thickness durable as the mask in formation of the hydrophilic films 24.
Next, the first liquid flow paths 51 are formed by dry etching from the first surface 21 side.
As the method of forming the first liquid flow paths 51, laser processing is usable, besides the dry etching. A depth of each of the first liquid flow paths 51 is already determined by the thickness of the substrate 10 and the shape of the second liquid flow path 52 already formed, but is desirably about 30 μm to 300 μm.
Next, details of the process of filling the first portions 61 and the second liquid flow path 52 formed by the above-described method with the filler 15 are described with reference to
Further, as the idea of the present disclosure, the filler 15 is dropped onto the inclined surface 23 of the inner wall of the second portion 62, is caused to move and flow along the inclined surface 23, thereby filling each of the first portions 61 with the filler 15. Thus, at the time of filling, it is desirable to drop the filler 15 from just above the inclined surface 23 so that the filler 15 moves along the inclined surface 23.
Further, since the hydrophilic films 24 are provided on the wall surfaces of the first portions 61, the aqueous filler 15 easily flows along the inner walls of first portions 61 more preferentially. This makes it possible to prevent bubbles from entering a space between the inner wall of each of the first portions 61 and the filler 15, and to further prevent inclusion of bubbles with the filler 15. Since the filler 15 can be applied without trapping bubbles, it is possible to form the ejection port forming member 9 in the subsequent step without deteriorating flatness.
In a case where the hydrophilic treatment is performed only on the wall surfaces of the first portions 61, the filler 15 flows into the first portions 61 without remaining on the inclined surface 23 as compared with a case where the hydrophilic treatment is also performed on the inclined surface 23 of the inner wall of the second portion 62. In other words, a filling rate of the filler 15 is improved, and the filling is performable with a smaller amount of filler, which leads to cost reduction.
As a method of forming the ejection ports 11, a common photolithography technique is usable.
As described above, in the manufacturing process of the recording element substrate, even in a case where the liquid ejection port is formed perpendicularly to the substrate, the filler 15 can be applied without trapping bubbles, which makes it possible to manufacture the recording element substrate with high manufacturing accuracy.
In the present exemplary embodiment, the method of manufacturing the substrate 10 provided with the liquid supply port 13 including the first portions 61 and the second portion 62 is described; however, it is sufficient to prepare such a substrate 10.
As the above-described liquid supply port 13, the example in which a center axis of each of the first portions 61 and a center axis of the second portion 62 are shifted from each other is described; however, the center axis of each of the first portions 61 and the center axis of the second portion 62 need not be shifted from each other. In the case where the center axis of each of the first portions 61 and the center axis of the second portion 62 are shifted from each other, the filler 15 can easily flow along the inclined surface when the filler 15 is applied. This causes the filler 15 to flow from each of the inner walls 61a connected to the inclined surface 23, and the possibility that bubbles are trapped with the filler 15 can be expected to be further reduced. The center axis of each of the first portions 61 is a center axis passing through a center of each of the first portions 61 and extending in a direction from the second surface 22 toward the first surface 21. Likewise, the center axis of the second portion 62 is a center axis passing through a center of the second portion and extending in the direction from the second surface 22 toward the first surface 21.
Further, a distance between the center axis of each of the first portions 61 and the center axis of the second portion 62 in the transverse direction is denoted by D. At this time, the distance D is desirably set as large as possible within a range where an opening end of each of the first liquid flow paths 51 does not exceed an opening end of the second liquid flow path 52, in consideration of opening dimensions of both of the first liquid flow paths 51 and the second liquid flow path 52.
Further, in
Further, the hydrophilic film according to the present exemplary embodiment indicates a hydrophilic film having a contact angle of 70 degrees or less. Further, to cause the filler 15 to easily flow, the contact angle of the hydrophilic film is desirably 40 degrees or less that is commonly regarded to be hydrophilic. The contact angle according to the present exemplary embodiment indicates a dynamic receding contact angle of pure water on a member surface. Typically, the dynamic receding contact angle can be measured by an extension contraction method in which a liquid droplet is dropped onto the member surface, and then the behavior of the liquid droplet is measured when a liquid is injected and absorbed.
In the present exemplary embodiment, the liquid-flow-path wall-surface protection film 18 is formed on the wall surface of the second liquid flow path 52 in
Further, in addition to formation of the hydrophilic films 24 on the inner walls of the first portions 61, a water-repellent film may be formed on the inclined surface 23 of the inner wall of the second portion 62. At this time, in the step of forming the hydrophilic films 24 on the inner walls of the first portions 61, it is necessary to form the liquid-flow-path wall-surface protection film 18 on the inclined surface 23 of the inner wall of the second portion 62, and in the step of forming the water-repellent film on the inclined surface 23 of the inner wall of the second portion 62, it is necessary to form the liquid-flow-path wall-surface protection films 18 on the inner walls of the first portions 61. As a result, it is possible to form the desired films on both of the wall surfaces. The formation of the hydrophilic films and the formation of the water-repellent film may be performed in any order. However, the hydrophilic films 24 are desirably formed on the inner walls of the first portions 61 after the water-repellent film is formed on the inclined surface 23 of the inner wall of the second portion 62 because the formation of the hydrophilic films 24 formed on the inner walls of the first portions 61 further contributes to the filling rate of the filler 15.
In the formation of the water-repellent film, the liquid-flow-path wall-surface protection film 18 desirably has a film thickness of, for example, about 2 μm to 10 μm as in the formation of the hydrophilic films, but may have any thickness as long as it is durable as the mask in the formation of the water-repellent film.
The water repellency as used herein means that, when a water droplet is in contact with a member, the water droplet does not cause the member to get wet and does not spread over the member, and it is determined whether the water-repellent film has been formed on the member, by measuring the contact angle of a surface of the member. The water-repellent film according to the present exemplary embodiment indicates the water-repellent film having the contact angle of 110 degrees or more.
A modified example of the first exemplary embodiment of the present disclosure is described. In the following description, portions different from the first exemplary embodiment are mainly described, and descriptions of portions similar to the first exemplary embodiment are omitted.
A method of manufacturing a recording element substrate according to the modified example is different from the method of manufacturing the recording element substrate according to the first exemplary embodiment in that a resin dissolved in an oil solvent, i.e., an oil filler is used. As the oil filler, an oil filler that is removable in a subsequent step is usable. Further, different filler removing materials can be used depending on the type of the filler.
In the modified example, the water-repellent films are formed at least on the inner walls of the first portions 61. As a result, in a case where the oil filler is used, the oil filler easily flows along the inner walls of the first portions 61 more preferentially. In other words, it is possible to prevent bubbles from entering the space between each of the inner walls of the first portions 61 and the filler, and to prevent bubbles being trapped with the filler. The contact angle of the water-repellent film according to each exemplary embodiment is 110 degrees or more; however, the contact angle of each of the inner walls of the first portions 61 in this modified example is desirably 150 degrees or more in order to cause the oil filler to easily flow along the first portions 61.
Further, in the modified example, the water-repellent films are formed on the first portions 61; however, the water-repellent film may be formed on the inclined surface 23 of the inner wall of the second portion 62. In this case, the step of forming the liquid-flow-path wall-surface protection film 18 on the wall surface of the second liquid flow path 52 may not be performed.
In a case where the water-repellent films are formed only on the wall surfaces of the first portions 61, the filler 15 flows into the first portions 61 without remaining on the inclined surface 23 as compared with a case where a water-repellent film is also formed on the inclined surface 23 of the inner wall of the second portion 62. In other words, the filling rate of the filler 15 is improved, and the filling is performable with the smaller amount of filler, which leads to cost reduction.
Further, in addition to formation of the water-repellent films on the inner walls of the first portions 61, the hydrophilic film may be formed on the inclined surface 23 of the inner wall of the second portion 62. In this case, in the step of forming the water-repellent films on the inner walls of the first portions 61, it is necessary to form the liquid-flow-path wall-surface protection film 18 on the inclined surface 23 of the inner wall of the second portion 62, and in the step of forming the hydrophilic film on the inclined surface 23 of the inner wall of the second portion 62, it is necessary to form the liquid-flow-path wall-surface protection films 18 on the inner walls of the first portions 61. As a result, it is possible to form the desired films on both of the wall surfaces. The formation of the water-repellent films and the formation of the hydrophilic film may be performed in any order. However, the water-repellent films are desirably formed on the inner walls of the first portions 61 after the hydrophilic film is formed on the second portion 62 because the formation of the water-repellent films formed on the inner walls of the first portions 61 further contributes to the filling rate of the filler 15.
A configuration of a recording element substrate according to a second exemplary embodiment of the present disclosure is described. In the following description, portions different from the first exemplary embodiment are mainly described, and descriptions of portions similar to the first exemplary embodiment are omitted.
The third liquid flow paths 53 correspond to the first liquid flow paths 51, and the fourth liquid flow path 54 corresponds to the second liquid flow path 52. Further, the third liquid flow paths 53 are also referred to as fourth portions 64. In the fourth liquid flow path 54, a portion where an inner wall is inclined is referred to as a fifth portion 65, and a portion where one end is connected to an inclined surface 28 of an inner wall of the fifth portion 65 and the other end is perpendicularly connected to the second surface 22 is referred to as a sixth portion 66. In other words, in
In
In the second exemplary embodiment, the liquid circulates through the second liquid flow path 52, the first liquid flow paths 51, the pressure chambers 12, the third liquid flow paths 53, and the fourth liquid flow path 54 in this order.
In the manufacture of the circulation-type recording element substrate, the inclined surface 23 and the inclined surface 28 cause the filler to flow downward from one side (inclined surface 23 and inclined surface 28) instead of flowing downward (toward first portions 61 or fourth portions 64) over the entire width of the liquid supply port as in the conventional example. Thus, as in the first exemplary embodiment, the filler 15 flows from the inner walls 61a connected to the inclined surface 23 toward the inner walls 61b and from inner walls 64a connected to the inclined surface 28 toward inner walls 64b, thereby being applied without trapping bubbles.
In the case of using the aqueous filler 15, the filler 15 easily flows along the inner walls of the first portions 61 and the inner walls of the fourth portions 64 more preferentially because the hydrophilic films are formed on the inner walls of the first portions 61 and the inner walls of the fourth portions 64. This makes it possible to prevent bubbles from entering spaces between the filler and both of the inner walls of the first portions 61 and the inner walls of the fourth portions 64, and to further prevent bubbles from being trapped with the filler 15s. Further, since the filler 15 can be applied without trapping bubbles, it is possible to form the ejection port forming member in the subsequent step without deteriorating flatness.
In the case of using the aqueous filler as in the first exemplary embodiment, the hydrophilic films or the water-repellent films may be formed on the inclined surface 23 of the inner wall of the second portion 62 and the inclined surface 28 of the inner wall of the fifth portion 65, in addition to the inner walls of the first portions 61 and the fourth portions 64.
Further, in the case of using the oil filler as in the modified example of the first exemplary embodiment, the water-repellent films are formed on the inner walls of the first portions 61 and the fourth portions 64. At this time, in addition to the first portions 61 and the fourth portions 64, the water-repellent films or the hydrophilic films may be formed on the inclined surface 23 of the inner wall of the second portion 62 and the inclined surface 28 of the inner wall of the fifth portion 65.
Further, the recording element substrate used for the circulation-type liquid ejection head includes a large number of liquid flow paths. Thus, there is a possibility that bubbles are trapped in the liquid flow paths, which largely influences on flatness of the substrate surface. Therefore, the configuration according to the present exemplary embodiment is suitable for that of the recording element substrate used for the circulation-type liquid ejection head.
To reduce a distance between the first liquid flow paths 51 and the third liquid flow paths 53, the first liquid flow paths 51 and the third liquid flow paths 53 are desirably arranged to have relationship of mirror inversion (right/left inversion) as illustrated in
Further, in the present exemplary embodiment, it is sufficient to prepare the substrate 10 provided with the liquid collection port 14 including the fourth portions 64 and the fifth portion 65, as in the first exemplary embodiment.
The present disclosure is not limited to the above-described exemplary embodiments. The present disclosure can be variously changed and modified without departing from the ideas and the scope of the present disclosure. Examples according to the present disclosure are described below based on the above-described exemplary embodiments.
A first example is described below. In a case where a formation process and a structure are similar to the formation process and the structure according to any of the above-described exemplary embodiments, descriptions thereof with reference to the drawings are omitted.
As for the position of the inclined surface 23 of the inner wall of the second portion 62, an apex of inclination of the inclined surface 23 on a side close to the first surface 21 is formed at a position of 50 μm from the first surface 21 in a depth direction of the substrate. The angle formed by the inner wall of each of the first portions 61 and the inclined surface 23 of the inner wall of the second portion 62 is 125.3 degrees.
The distance D between the opening center of the second liquid flow path 52 and the opening center of each of the first liquid flow paths 51 in the transverse direction is 150 μm.
A second example is described below. In the case where a formation process and a structure are similar to the formation process and the structure according to any of the above-described exemplary embodiments, descriptions thereof with reference to the drawings are omitted. Further, in a case where specific dimensions, positional relationship, and the like are similar to the specific dimensions, the positional relationship, and the like according to the first example, descriptions thereof are omitted.
According to the exemplary embodiments of the present disclosure, it is possible to provide a recording element substrate that can prevent bubbles from getting trapped with a filler when a liquid supply port provided perpendicularly to the substrate is filled with the filler, and a method of manufacturing the recording element substrate.
Embodiments of the present disclosure can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described Embodiments and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described Embodiments, and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described Embodiments and/or controlling the one or more circuits to perform the functions of one or more of the above-described Embodiments. The computer may include one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read-only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc™ (BD)), a flash memory device, a memory card, and the like.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2022-009843, filed Jan. 26, 2022, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2022-009843 | Jan 2022 | JP | national |